<body>
<script>
var canvas, ctx;
canvas = document.createElement("canvas");
canvas.width = 200;
canvas.height = 200;
document.body.appendChild(canvas);

ctx = canvas.getContext("2d");
ctx.fillStyle = 'rgba(0,0,255,1)';
ctx.fillRect(60,60,75,50);
</script>
</body>